Epigenetics, suicide, and voulez-vous coucher avec moi?

By Bud Martin

Child abuse and the adult brain

It’s no secret child abuse can cast a dark cloud on victims even once they’re grown up. Now a McGill study, published in the journal Nature Neuroscience, points to a biological reason why these adults run a higher-than-normal risk of anxiety, depression, substance abuse and suicide. The researchers – Patrick McGowan, Michael Meaney, Aya Sasaki, Ana C. D’Alessio, Sergiy Dymov, Benoît Labonté, Moshe Szyf and Gustavo Turecki – found that childhood abuse or neglect changes gene expression, creating adults who are significantly more sensitive to stress. The study received a flurry of media attention, including coverage in the New York Times, Science, the Telegraph, the Globe and Mail, the Montreal Gazette, Le Devoir, La Presse, American Public Radio, Quirks and Quarks, the Boston Globe, New Scientist, ABC, BBC, Radio-Canada, National Geographic and CTV.

The findings are the latest discovery in the growing field of epigenetics, which looks at how environment affects gene function. (The DNA itself, however, is unchanged.) Using the Douglas Mental Health University Institute’s Quebec Suicide Brain Bank, the researchers compared the brains of 12 child abuse survivors who committed suicide as adults with those of 12 suicide victims who weren’t abused as children. (There was also a control group of 12 brains of non-abused people who died from other causes.) They found that, in the brains of people who had been abused, the genes responsible for clearing the hormone cortisol, which is produced under stress, were 40 per cent less active – meaning abuse survivors have much greater difficulty dealing with stress. “The implications at this stage are you want to identify these people and then probably offer them some sort of intervention,” co-author Szyf, epigenetics pioneer and a McGill pharmacology and therapeutics professor, told the CBC. He added that the findings may one day result in drugs to reverse the epigenetic changes and, hopefully, dramatically improve the quality of life for adult survivors of child abuse.

Songs sung blue

A recent study published in the American Journal of Preventative Medicine suggests a link between exposure to raunchy pop music lyrics and increased sexual behaviour in teens – but Daniel Levitin, McGill cognitive neuroscientist and author of the bestselling This Is Your Brain on Music, suggests we shouldn’t lay all on the blame on dirty talk. He told the Canadian Press that, although the study “clearly adds to our body of knowledge about the connection between musical lyrics and … experiences of young people,” it is important to consider that there may be “some third factor out there in the world that’s causing [young people] both to engage in [risky sexual activity at a younger age] and to seek out this music.” The study focused on Pittsburgh teens, and Levitin cautions against extrapolating the findings. “They didn’t do a study across all of the United States, let alone across all of North America. It’s a possible limitation of the study. Maybe these results apply only to Pittsburgh, and you wouldn’t find similar associations in Philadelphia or Calgary or Prince Edward Island, for that matter.”